Discount Calculator
This free discount calculator works out the sale price and savings from an original price and a discount percentage, and correctly handles stacked discounts, an additional percentage taken off the already-discounted price, not the original. Enter your numbers and every result updates instantly.
How to Use It
- Enter the original price.
- Enter the discount percentage.
- Optionally enter a second, additional discount percentage for stacked/sequential discounts.
- The discount amount, sale price, and (if applicable) final price and total savings update instantly.
How It Works
The first discount is a straightforward percentage of the original price: discount amount = original price × (discount % ÷ 100), and sale price = original price − discount amount. The optional additional discount works the same way, but it's calculated on the sale price, not the original, exactly how a store applies a second, stacked promotion on top of an already-discounted item.
Formulas
discount amount = original price × (discount % ÷ 100)
sale price = original price − discount amount
final price = sale price − (sale price × additional discount % ÷ 100)
A worked example: an $80 item at 25% off comes to a $20 discount, for a $60 sale price. Add an extra 10% off on top of that $60 (not the original $80), and that's a further $6 off, for a final price of $54. Total savings: $26, which works out to 32.5% off the original price, not the 35% you'd get by simply adding 25% and 10% together. The gap between 32.5% and 35% is exactly the effect of the second discount applying to a smaller base than the first.
Everything runs client-side in your browser. No prices you enter are sent anywhere or stored.
Frequently Asked Questions
Why is 25% off plus an extra 10% off not the same as 35% off?
Because the second discount applies to the already-discounted price, not the original. On an $80 item, 25% off takes it to $60. An extra 10% off that $60 (not the original $80) is $6, for a final price of $54, a total of 32.5% off, not 35%. Stacked percentages never simply add, since each one is calculated from a smaller base than the last.
How do I figure out the original price from a sale price and discount?
Divide the sale price by (1 minus the discount as a decimal). A $60 sale price after a 25% discount means the original price was 60 ÷ (1 − 0.25) = 60 ÷ 0.75 = $80. This calculator computes forward (original price to sale price); this reverse calculation is a manual one-step follow-up if you only know the discounted price.
How is this different from the Percentage Calculator?
The Percentage Calculator answers general percentage questions (what is X% of Y, what percent is X of Y, percentage change from X to Y). This tool is purpose-built for shopping discounts specifically, including the stacked "extra X% off" scenario retailers commonly offer, which the general Percentage Calculator has no dedicated field for.
Does the order of two stacked discounts matter?
No, mathematically, applying 25% off then 10% off gives the exact same final price as applying 10% off then 25% off. Both are just two multiplications applied to the original price, and multiplication order doesn't change the result. What does matter is that each discount is calculated on the price after the previous one, not on the original price both times.
Can I use this for a discount over 100%?
No, a discount can't exceed 100% of the price (that would mean the item costs less than nothing), so this calculator rejects any discount percentage over 100. A 100% discount is accepted and correctly returns a final price of $0.
Does this calculate sales tax on top of the discounted price?
No, this tool only handles the discount itself. If you also need to add sales tax to the final discounted price, our general Percentage Calculator's "X% of Y" panel can compute the tax amount on that final price, since tax is a separate percentage calculation applied after the discount, not part of the discount math itself.
What counts as a good discount to look for when shopping?
That depends entirely on the item and how the discount is presented, not something this calculator judges. What it does help with is seeing through marketing framing: a "25% off, plus an extra 10% off" banner sounds like 35% off, but as shown above it's actually 32.5%. Running the real numbers rather than adding the percentages in your head is the main practical use of this tool.